LIFE HISTORY AND HABITS. 23 
placed in the center of a large petri dish. Within 10 minutes all the 
wireworms were under it. This experiment was repeated by using a 
piece of damp cardboard the size of the beet slice and again timing 
the wireworms. In this test all the larvae finally gathered under the 
cardboard to escape the light, but a longer time was required before 
this took place. These tests were repeated several times as checks 
and always gave the same results, so it is evident that the larvae are 
able, to a small extent, to locate food. 
The larvae begui feeding noticeably, though lightly, very soon 
after hatching. A fresh slice of sugar beet was placed in the cage 
every day, and when each slice was removed the muiute black feedmg 
marks could be noticed. The depressions made by the feediag could 
be made out only with a hand lens, but the black staLa, so character- 
istic of wireworm injury, had spread out and was quite conspicuous. 
The wireworms grow quite rapidly duruig the first two or three 
weeks, and it might be added that this is the only time in their long 
larval life when their growth is apparent. They approxunately 
double in size in this time and then remain about the same size until 
they molt. At the time of their first molt they take a sudden jump 
in size and froij^ this time on then- growth is very slow. 
An attempt was made to trace the molts with these wireworms, 
but unfortunately it had to be abandoned. The death rate in the 
exposed cages was so high that it soon became apparent that none 
could be brought entirely through in this manner. Added to the 
difficulty was the fact that since their time of molting was so irregular 
only a few could be kept in a single cage. After about a thousand 
larvae had died in these cages it was concluded that it was impossible 
to carry the observations to completion with the forms of rearing 
apparatus at hand. The cast skins of the larvae could not be found, 
owing to their small size and transparency, and the only molts that 
could be traced were in the case of certain larvae which increased in 
size quite noticeably overnight. The increase in the width of the 
head was found to be the best test. 
From time to time the soil in the fiowerpots containmg the bulk of 
the wireworms was carefully examined to see whether anythiug could 
be learned concerning the feeding habits of the larvae under natural 
conditions. In every case the larvae were found scattered rather 
generally through the soil, and as many of them were found around 
the edges of the pot as directly around the beet root. Since the root 
hairs were scattered pretty generally through the soil it seemed prob- 
able that the larvae fed on them. This was further indicated by the 
fact that no feeding marks could be found on the main beet root. 
At any rate it is safe to say that, from the standpoiut of injury due 
to their feeding, the wireworms during the first year of their larval 
life may be disregarded. Larvae were generally found from 1 to 3 
